Modified live-virus rabies vaccine produced from flury high egg-passage virus grown on an established canine-kidney cell line: three-year duration-of-immunity study in dogs
Brown, A.L.; Merry, D.L.; Beckenhauer, W.H.
American Journal of Veterinary Research 34(11): 1427-1432
1973
ISSN/ISBN: 0002-9645 PMID: 4748726 Document Number: 65160
A modified live-virus rabies vaccine, prepared by growing high egg-passage (HEP) Flury strain on an established canine kidney cell line, was tested in dogs to determine its immunogenicity. Six groups of dogs were vaccinated either i/m or s/c with a field dose of vaccine or with 1/10 or 1/100 of a field dose. Blood samples were collected for serological evaluation before inoculation, at 1, 2, 3, 4, and 8 weeks after vaccination, and at 6, 12, 24 and 36 months after vaccination. Dogs were challenge inoculated with street rabies virus 41 months after vaccination for the three groups inoculated i/m and 38 months for the three groups inoculated s/c. Additional blood samples were collected for serological evaluation before challenge inoculation and at 30 and 90 days or terminally after challenge inoculation. All dogs inoculated i/m, except one dog inoculated with 1/100 of the field dose, were protected against challenge inoculation of street rabies virus. Of the dogs inoculated s/c, 17 of 29 dogs were protected by the field dose, but only poor protection was obtained in the dogs inoculated with diluted vaccines (1/10 or 1/100 of field dose). All uninoculated control dogs died from rabies. Serological evaluation indicated the i/m route of inoculation as producing the better immune response. A dose-response effect apparently occurred according to the amount of vaccine inoculated. After challenge inoculation, the increase in rabies antibody titre indicated an anamnestic response to street rabies virus.